1. Technical Field Of The Invention
This invention relates to charging in a telecommunications network and, more particularly, to the use of SS7 TCAP protocols for communicating accounting messages.
2. Description of Related Art
Developments and improvements in wireless telecommunications switching systems have allowed wireless users to easily move from one physical location to another and still access and utilize the user's own telephone services and subscriber features. One example of this type of service is roaming. Roaming allows the subscriber to move from one city covered by a first telephone company to another city covered by a second telephone company and still use his or her cellular telephone unit. Currently, telephone services toward a roaming subscriber are allowed after the second telephone company requests and receives confirmation data regarding the roaming subscriber's service from the first telephone company. After services have been provided to the roaming subscriber, the second telephone company collects the charging data and sends the information, usually in a batch file, to a centralized administrative center for further analysis. It is at this point that the rightful owner or the centralized billing administrative system determines illegal use of the service by a clone. Since the transfer of the billing batch file is usually done a few days after the actual services have been provided to the roaming subscriber, there is an undesirable time delay before possible fraud is detected.
Cellular radio telephones fall into two main categories, namely mobiles and hand portables. Conventionally, each cellular telephone whether mobile or hand portable has its own unique telephone number by which it may be accessed from other cellular telephones or fixed-wired conventional telephones. The full telephone number is stored in a memory (e.g. a ROM, PROM, or RAM) known in the art as a number assignment module (NAM), that is coupled to the control circuits, usually a microprocessor, of the cellular telephone. When an infringer "steals" a valid cellular telephone number and duplicates the number in another cellular phone (i.e., cloning), the infringer is free to use the telephone service while incurring the charges to the rightful subscriber. Unfortunately, when the roaming subscriber is using the service without proper authority from the rightful owner of the service, the centralized administrative center or the rightful owner of the services is not notified of the illegal usage until the billing records from the second telephone company are received.
A number of security checks have been placed in the system to filter and detect fraudulent calls before they are made. However, it would also be a desirable capability for telecommunications networks to allow services to roaming subscribers while being able to detect fraud on the system on a substantially real time basis after the call is made. The term "real time" for the purposes of the present invention implies a situation where events are handled or notified with minimum time delay after they actually occur in the system. This capability would allow the networks to minimize illegal usage of telecommunication services by narrowing the gap between the time the service is provided to an infringer and the time the centralized administrative center receives the billing records and details the fraud. This capability would also fully support features and services within the telecommunications network that require both billing records and normal telecommunications data at the same time.